The present invention relates to a new and distinctive variety of apple tree belonging to a medium-maturing apple cultivar, and more particularly, relates to an apple variety having high quality and high disease resistance for eating raw and for processing.
Regarding medium-maturing apple varieties, although xe2x80x98Jonathanxe2x80x99 and xe2x80x98Starking Deliciousxe2x80x99 were widely cultivated in the past, they were not popular due to their taste and poor storage quality, and there are no main medium-maturing apple varieties now known to us. Thus it was necessary to breed a main medium-maturing apple variety immediately.
Accordingly, the present breeders crossed xe2x80x98Hatsuakixe2x80x99, which is an excellent variety for both eating raw and for processing, with xe2x80x98Fujixe2x80x99, which is a main economical variety, to obtain excellent medium-maturing apple varieties having good fruit quality and high productivity. Namely, the purpose of the invention is to avoid russet on fruit surface and to improve storage quality of the medium-maturing variety xe2x80x98Hatsuakixe2x80x99 and to breed a new and distinct variety of medium-maturing apple variety having excellent disease resistance for eating raw and for processing.
To produce the new variety, the breeders crossed xe2x80x98Fujixe2x80x99, which had been cultivated at the Morioka branch of the Fruit Tree Research Station (currently the Apple Research Center, the National Institute of Fruit Tree Science), in Japan, and xe2x80x98Hatsuakixe2x80x99, in 1976, and obtained seeds. The seeds obtained were utilized for sowing and raising seedlings at said branch, in 1977, and the resulting seedlings were then grafted on xe2x80x98M.27xe2x80x99, the most dwarfing rootstock, to accelerate bearing, in 1978, and 127 individuals were set in 1980.
The trees bore fruit in 1983 and one was selected in the primary selection as a good medium-maturing individdual in 1986. The present invention is directed to an apple tree xe2x80x98Kotaroxe2x80x99, which is one individual from amount 127 individuals derived from the cross xe2x80x98Fujixe2x80x99 (♀) (the seed parent) and xe2x80x98Hatsuakixe2x80x99 (♂) (the pollen parent), and was given an individual number xe2x80x9c601xe2x80x9d during testing. The tree was selected as a favorable line of trees, which have a line name Ringo Morioka 56 Go, have been provided for local adaptability tests since 1991, and were examined to determine the various characteristics thereof, over a period of seven years from April 1991 to March 1998. As a result, it was found that, for example, fruit of the trees had the desired characteristics, such as quality, storage quality and yield, as a medium-maturing apple variety, and the tree was distinguishable from the parent varieties, xe2x80x98Fujixe2x80x99 and xe2x80x98Hatsuakixe2x80x99, as well as a control variety xe2x80x98Jonagoldxe2x80x99. Accordingly, the breeders denominated this variety as xe2x80x98Kotaroxe2x80x99, in accordance with this invention. The genus and species of the tree is Malusxc3x97domestica. 
Of the varieties, xe2x80x98Fujixe2x80x99 is a variety generated from a cross between xe2x80x98Ralls Janetxe2x80x99 and xe2x80x98Deliciousxe2x80x99.
Of the varieties, xe2x80x98Hatsuakixe2x80x99 is a variety generated from a cross between xe2x80x98Jonathanxe2x80x99 and xe2x80x98Golden Deliciousxe2x80x99.
The breeders asexually reproduced this new and distinctive variety of apple tree xe2x80x98Kotaroxe2x80x99, by grafting on rootstock xe2x80x98M.27xe2x80x99 (U.S. Plant Pat. No. 3,793), at a number of Fruit Tree Research Stations in Morioka City, Iwate prefecture, Japan, and confirmed the homogeneity and stability of xe2x80x98Kotaroxe2x80x99 according to the present invention. The instant plant retains its distinctive characteristics and reproduces true to type in successive generations.
Of the above varieties, only M.27 is known to us as having been patented in the United States.
An application for this new variety of apple tree, xe2x80x98Kotaroxe2x80x99 under the Seeds and Seedlings Law of Japan, was filed on Apr. 9, 1998, under the filing number 10857.
The original tree of this apple tree is held at the Apple Research Center of the National Institute of Fruit Tree Science, Ministry of Agriculture, Forestry and Fisheries, residing at 92 Nabeyashiki, Shimokuriyagawa, Morioka City, Japan.
This new variety of apple tree is vigorous and spreading, and many spurs and axillary buds are formed.
The leaves of the tree are rounded and serrated.
At Morioka City, Iwate prefecture, Japan, the trees have a flowering time around May 21st which is about 4 days later than that of xe2x80x98Jonagoldxe2x80x99 and xe2x80x98Fujixe2x80x99. The number of flowers per cluster is about 4-6 and flower is single and number of petals per a flower is 5. The flower color opened is white and unopened it is deep pink. The size of the flower is small, the same as that of xe2x80x98Ralls Janetxe2x80x99. The amount of pollen is high and the present variety is self-unfruitful (the variety is not fructified by self-pollination). As the type of S gene of the present variety is (S3, Sf), though it is cross-incompatible with xe2x80x98Akibaexe2x80x99, xe2x80x98Shinsekaixe2x80x99 and xe2x80x98Gunmameigetuxe2x80x99 (unpatented to our knowledge), the cross-compatibility with common cultivars except the above varieties is high.
Early fruit drop and preharvest drop of fruit are few and the present variety shows high productivity. Of the main diseases, the tree is resistant to Alternaria blotch, but is susceptible to scab. It has not been recognized so far that any disease or insect except for the above, is significant.
The ripening of the present fruit occurs in late October at Morioka, as same as that of xe2x80x98Jonagoldxe2x80x99. The size of the fruit is medium and averages about 250 g, and is slightly smaller than that of xe2x80x98Fujixe2x80x99, and the shape of the fruit is rounded. The type of over color of skin of the fruit is red-purple (60A by R.H.S.) and it has a good appearance and has a tendency to have a silvery mottle. The occurrence of russet on the surface of the fruit is slight.
The flesh of the present fruit contains about 14-15% Brix of total sugar, and about 0.4 g/100 ml of malic acid, and further the flesh is firm and juicy, and has a moderate sweetness and weak sourness, an aroma, provides a good sweet-sour balance and has excellent eating quality. The storage quality of the fruit is relatively good, but inferior to that of xe2x80x98Fujixe2x80x99, and is about 25 days at room condition and about 70 days in cold storage.
Compared with the seed parent, xe2x80x98Fujixe2x80x99, the present variety is distinguishable in that ripening of the fruit is earlier by about 2 weeks than that of xe2x80x98Fujixe2x80x99, the type of over color of the skin of the present variety is solid, i.e. not striped, whereas that of xe2x80x98Fujixe2x80x99 is striped, the fruit of the present variety does not have tendency to an inclination of the axis, as does xe2x80x98Fujixe2x80x99, and the flesh of the present variety has a medium aroma, whereas that of xe2x80x98Fujixe2x80x99 is weak.
Compared with the pollen parent, xe2x80x98Hatsuakixe2x80x99, the present variety is distinguishable in that the ripening of the fruit is later by about 25 days than that of xe2x80x98Hatsuakixe2x80x99, the flesh of the present variety is firm, acidity is weak and the flesh has a moderate sweet-mellow aroma.
Compared with xe2x80x98Jonagoldxe2x80x99, the present variety is clearly distinguishable in that the leaves and the fruit of the present variety are smaller than those of xe2x80x98Jonagoldxe2x80x99, the flesh of the present variety is firm, acidity of that is weak, the flesh has an aromatic flavor, and the greasiness of the peel after storage is weak.
The color references are made to The Royal Horticultural Society Colour Chart (R.H.S.) except where general terms of ordinary significance are used.